Can you solve the seven planets riddle? - Edwin F. Meyer 

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Some food for thought. If Harry and Ron were both perfect logicians, they could theoretically continue with that same line of questioning ( "Do you know now?" "No" "Me neither. Do you know now?" over and over again) and they would eventually figure out how many times the other person has seen Titanic, even if its a really high number. The logic for it works as follows: Since neither of them know the answer from the start (Ron saying "I have no idea" and Harry saying "Me neither") they can both safely assume they've both watched Titanic at least twice. This is because if one of them only saw it once, they would immediately know the other person's seen it more times. However, when Harry asks Ron "Do you know now?", one of two things can happen. Ron could have seen it twice and deduced that Harry must have seen it three times (because they both know they've both seen it at least twice), and Ron says "yes! I know now" OR Ron saw it MORE than twice and answers with "No I still don't know". If Harry responds "Me neither" that means he TOO must have seen it more than twice, and at that point they both know they have both seen Titanic at least three times. This can continue on ad infinitum until the answer is revealed. For example, if Ron saw Titanic... say... 15 times (dear lord), when they reach the point where they both know they have both seen Titanic at least 15 times, Ron will answer with "Yes I do know now!" properly deducing that Harry must have seen it 16 times. All of this said, they could simply just TELL each other how many times they've seen Titanic. But if I saw Titanic 15 times, I wouldn't want to tell anyone either ;p If anyone actually read this, wow good job.

Assuming Harry and Ron are perfect logicians, Harry has watched it 4 times, Ron 3. Here's the steps: A). Harry asks Ron if he's seen it more. This shows the score isn't H1, R2, because if it were, Harry would realize since he's only seen it once, Ron would have had to see it twice, and wouldn't have texted Ron to ask. Therefore, Harry has seen it at least twice. B) Ron says he doesn't know. This shows the score isn't H2, R1, because if it were, Ron would realize since he's only seen it once, Harry would have had to see it twice. Therefore, Ron has to have seen it twice. C) Ron also know, that because Harry asked in the first place, Harry *also* must have seen it at least twice (see A). If Ron had seen it exactly twice, that means Harry has watched it three times, and Ron would know the answer. Because he didn't, this means Ron has seen it at least 3 times. D) Because (B) and (C), Harry knows Ron has seen it at least 3 times. But he still doesn't know if he's seen it more or not. This means he's seen it more than twice (because he'd know that he'd seen it twice so ron saw it 3 times), and he's seen it more than three times (because he'd know if he saw it three times, then ron had watched it 4 times). Because Harry doesn't know, he's seen it at least 4 times. E) Now Ron knows! Because Harry has seen it at least 4 times, and he knows he himself only saw it 3 times, we have a match. Harry 4, Ron 3.

what makes you a eligible detective? *I solved a ted ed video before the timer ran out* Holy sh-

Me: Okay I'm gonna try to solve the riddle this time Inner me: You know you want to see that answer

Harry: "Hey, Ron! So how many times did you watch Titanic?" Ron: "Hey, Harry! I reckon I watched it 127 times. How about you?" Harry: "You're a sick sick man, Ron. I watched it only twice. The first time was when it was originally released, and the second time was when it came in 3D." Ron: "Oh. Okay. Bye bye then."

Tip for the rebels: Confirm they have green eyes Ask the police if they can leave

Why are Harry and Ron texting each other? Didn't they live in the same room?

Endorra = Endor Yavine Fore = Yavin IV PinBes = Bespin Tattooide = Tatooine Dagovah = Dagobah Aldoran = Alderaan Cashyyyyk - Kashyyyk

Just party on planet 3 until aliens arrive and then invite them over too for a big bang

I paused the video for two days until I finally got it! I was tired of not being able to solve these. These riddle videos are so good been following them for years, I love them! Keep'em up!

This riddle is really cool! I have seen the linear version before where all of the "planets" are aligned in 1 dimension. I haven't seen the split on the third planet before. It is also nice to see that the same line of reasoning works in both cases. The key to note in these types of puzzles is when given that one side MUST do something in a oscillatory fashion, you can take advantage of that. For example, this is applicable in certain chess positions. Surprisingly, the linear case comes down to needing 2(n-2) steps to win, but this branched case also seems to need the same number of steps.

“Mom, can I have a list of planets from Star Wars?” “We have a list of planets from Star Wars at home” The list of planets from Star Wars at home: 0:17

cant help but notice the ad-blocker plug-in on the screenshot @5:24

The rebels must not escape! *Darth Vader Breathing.*

I want an interactive version of the riddle, playable from both sides

One of the planets looks like a marshmallow

who else is just here for the relaxing voice?

comment section be like 70%: star wars 15%: harry potter 5%: actually did the riddle/bonus riddle other 5%: dem voice so soothing- other other 5%: green fly double mouth nose thingy

The Star Wars reference is strong with this video

Oh my gosh yay! I love these riddle videos 🙋🏻

That last riddle was like math problem solving: John and Larry like to play minecraft, there are 76 people on their server but only 40 players have been to space. How many teeth does the crocodile have?

Did anyone notice its the names of planets from star wars but wrong spelling

Bonus riddle answer - Harry asks Ron whether he had watched titanic more times, therefore he does not know himself. If he had watched it only once, then he would have known. Therefore- Harry watched titanic at least twice. Then Ron answers that he does not know. If Ron had watched titanic exactly twice then he would have known that Harry must have watched it 3 times, therefore Ron must have watched it at least 3 times. Harry then answers that he still doesn't know. If harry had watched it exactly 3 times, then he would have known that Ron must have watched it 4 times, and so he watched it at least 4 times. Ron then says that he does know whether he watched more times or not. That can only be the case if he watched it 3 times or 4 times, because then he would know that harry must have watched it 4 or 5 times respectively. So Ron must have watched titanic either 3 or 4 times, so their sum is 7.

This riddle was super ambigous. They never explained whether the rebels and we move at the same time or after one another and even in the explanation video it jumped back and forth between the two scenraios. That makes it so much harder to solve since you have no idea which ruleset is the correct one.

Why can't they just wait for them on planet #3?

If harry and Ron are smart, then the answer is JUST TEXT THE NUMBERS TO EACH OTHER

“Your friends harry, ron, and hermione” **sounds of harry potter fans screaming intensifies**

Please make more riddles more often!! Thank you!!😊 BTW I love your videos and I am inspired by them. Thanks you all for being amazing.

Ted Ed: Apprehend the group of rebels Me: I dont work for the empire

does no-one notice the rules at 1:08 go 1,2,3,5,6? WHERE IS 4!!!

No, but can you solve this riddle? “What goes up that must come down?” My self esteem 😭

The true bonus riddle is how and why does hermone know how many times Ron and Harry have seen Titanic

A friend of mine told me about this question last night, I found a similar solution but in my case the police car doesn't need to move more than one planet per hour (instead it stays on the same planet for two hours, basicaly it's the same trick): 2-3-4-3-6-6-3-2-3-4. This remind me chess. For example in an end-game of king and rook against king it's well known that to achieve checkmate you have to do a sort of "opposition" with kings and then push the rook in the same row/column of the opponent's king. To allow it, if the kings are not "synchronized", you need to loose a tempo by moving your rook. This is the same idea of loosing a tempo to "synchronize" cars by mooving of two planets or by staying on the same planet. Very interesting, thanks!

Did u realise all planets r names of Star wars planets/moons with the wrong spelling. Endor Yavin 4 Bespin(on which cloud city is) Tatooine Dagobah Alderaan Kashyyyk

TED-ed: can you solve the seven planets riddle? Me: ozo

I have always have fun on teded videos, but not this one, I hate the fact that the bonus riddle is not answered, I visit the ads, but it make me signing up, but after signing up? It told me to be premium member. duh.

The answer is 5 A) Harry asks Ron. It means H > 1 he wouldn't ask elsewhere. B) Ron doesn't know. It means R > 1. If it was he would've known. C) Harry still doesn't know. Therefore H > 2. D) Ron knows already. It means R < 4. If he watched it 3 times Harry watched 4 and if he watched twice Harry watched 3 times. If Ron watched Titanic 4 times, he wouldn't know if Harry did it 5 times. E) if Ron already knows the answer R < H. Otherwise Ron wouldn't know yet. And if H = 3 -> R = 2 If H = 4 -> R = 3 If H = 5 or more -> R doesn't know yet If H = 2 or less -> H would've already known before then. F) Left possibilities are R = 2 or 3 Sum of which is 5

Our school used this for their Math Olympiad. This helped a lot!

I solved it, but it is hard to explain the whole method without a picture. The key that makes it possible is to realize that for any given start position, all the other positions can only be accessed either on an even turn or an odd turn. There are only two possible pictures of even/odd positions, depending on their start position. You assume one picture first, and alternatingly check each arm at the appropriate even/odd spot, and then the middle again to check that they didn't move to a different arm. If you don't find them after 5 moves (checking each arm once and the middle twice), your initial assumption was wrong, and you must use the other map of the even/odd positions and check again for 5 more moves in the same way.

Doctor: you have 6 minutes to live Me: *watches video*

I want to clarify a few things for everyone who doesn't understand (as there are quite a few comments demonstrating some confusion): 1.) The layout of the planets is as shown in the video. There is no need for TED-Ed to explicitly state that the planets are in that layout as we are introduced to the planets by being shown that specific layout at 0:16 and are given no other possibilities. If the layout of the planets could be different, the video would have mentioned something along the lines of, "Let's assume the planets are in this configuration" or, "If the planets are in this configuration, we can use this method." It says neither, and just introduces the planets in the Y formation and never changes it. Therefore, there is no possibility of the planets in another formation. 2.) The warp feature simply allows the Police Cruiser to move between any two planets without them needing to be adjacent. The Rebel Beat-Up Smuggling Ship can only move between adjacent planets (see 0:34 to 0:45). Travel time between planets, regardless of how far apart they are, will take the same amount of time for both ships. (Yes, this is at odds with real-world physics. But treat it more like moving a game piece to a new spot as opposed to driving a car or flying a plane - as the video clearly intends.) Ultimately, each ship can move to a new planet each hour, or turn, only once because of the recharge time. 3.) The two ships cannot and will not meet during their jumps between planets. This is indicated in Rule #2 (1:08) which says, "Every hour, you MAY warp to any of the seven planets to search for the rebels there." Note the final word "there". This implies that the searching is *on* the planet not between planets. (Regardless, this point is absolutely demonstrated in the solution at point 4:13 to 4:15 when the Police move from Planet 3 to Planet 4 and the Rebels move from Planet 4 to Planet 3. If the Rebels could be found mid-flight, this move would not be possible.) 4.) Rule #3 (1:08) says, "Starting after your first search, the rebels MUST move every hour to a planet adjacent to their current location. They will not stay still." This very plainly states - along with the lines at 0:45 to 0:51 - that the rebels do not like to stay put and that they will relocate when they can. The only stipulation put on whether or not the rebels can relocate is the recharge time on their ship. The Rebels would never choose to stay put when they have the option to move. (Furthermore, this practically demonstrates that the Rebels do not know which planet the Police are on just as the Police do not know which planet the Rebels are on. If the Rebels knew, or could see, which planet the Police were on, they would either move in a different direction or just stay put. Since they do not have this information, they keep moving at every chance they get.) 5.) The "game", so to speak, began when the Rebels used their "turn" to pick a planet. Your turn begins with you choosing a planet to search. The hour it takes for the warp/jump features to recharge on the ships is the allotted search time. That is the end of turn 1 out of 10. Once the recharge/search hour is up, both players have another turn and can move again. The moves are made simultaneously, as both would move to a new planet as soon as possible, and a new search begins. End of turn 2 out of 10. Once that next hour is up, it is the start of another turn. This means that the Rebels cannot be on a planet you move to and then move while you are searching it but before you find them. Again, assume that this is like moving a game piece to a new space. Once both move, the search begins. If your move lands you on the same space that the Rebels are on, you find and capture them. 6.) Another note on Rule #2 (1:08), "Every hour, you MAY warp to any of the seven planets to search for the rebels there." You MAY move. This means that *you* may choose to stay put and see if the Rebels come to you. It is a valid strategy and one that MAY work in some scenarios. But you are not looking for a solution that works in *some* scenarios. Rule #6 (1:08), "Your sequence must be capable of finding the rebels in every possible scenario." If there is any way that the Rebels can escape when using a certain search option, that option is not a valid solution to the puzzle. (You can test your solution by playing as the Rebels and attempting to avoid the Police, who are searching according to your proposed solution. If you can escape, the solution fails. If you can't, it succeeds.) Your goal is to guarantee that you will catch the Rebels in 10 moves or less. without needing to know which planet they started on. If your solution allows for any escape, it cannot be trusted. 7.) It is possible the Rebels may decide to simply jump between 2 planets. As you do not know which planet they started on, simply staying on 1 planet in this scenario would never work unless you got lucky and chose either the planet they started on or the planet they move to second. And, as mentioned above, this solution is invalid as it does not guarantee success. There are a lot of riddles in the world that require you to have some bit of information that has not been given in the set-up and that you could not have known previously. These types of riddles are designed to be unsolvable and allow the "riddle" teller to laugh at you. This riddle is not one of those. It gives all the required information and the solution presented does not assume or use things that you are unaware of. It may require a bit of "outside the box" thinking, but that is what it and Brilliant is trying to teach you to do with these puzzles. Have I solved every TED-Ed riddle? No, of course not. But as far as I can remember, the ones I did not solve, and the logic behind them, were easy to understand once the solution was presented. In the end, if you think logically and are willing to work through the problem at hand, it can be solved. And, you might just learn something along the way.

TED EEDDD! I LOVE YOU♥

Can someone post the answer to the second riddle?

But the real riddle Ted ed want us to solve is: *is that green fly alien girl's mouth or nose?*

Time to watch another video to make yourself feel that you've gotten smarter, but we all know the reality.

Lol I always thought the purple guy's nose was his eyes Now I look above him and those eyes are his eyes MY LIFE WAS A LIE

0:17 Ted-Ed, listen to me. Did you just rip off 7 Star Wars planets!?

I haven't watched it, but I'm sure that I won't be able to do this as well.

Some instruction are unclear. Because i think the rebel and police are move in same time. It means when police in planet 2, and go to planet 1, rebel can go undetected from planet 1 to planet 2. Nice riddle tho.

i love how the planets are named after star war planets lol

electronic gadgets such as phones dont work in Hogwarts.......riddle is a LIE!!!!!!

Harry has green eyes soo...

Here’s the solution if someone’s looking: If someone had watched Titanic only once, then that person would know the answer immediately. Since both Harry and Ron did not know the answer initially, both must have watched it at least twice. Let us assume that Ron watched Titanic twice, and analyze the conversation in Ron's perspective. Ron knows that Harry watched Titanic either once or thrice. Thus initially Ron would not know if he watched Titanic more than Harry did. However, Harry said "me neither", which implies that Harry did not watch Titanic once. Hence Harry must have watched Titanic three times, which Ron now knows with certainty. So, Ron could reply "yes, indeed!". This time suppose that Ron watched Titanic three times. Then Ron knows that Harry watched Titanic either twice or four times. Again, Ron would not know if he watched Titanic more than Harry did. Now, assume that Harry watched Titanic two times. Then Harry initially knows that Ron watched Titanic either once or thrice. After listening to Ron's answer "I have no idea", Harry would then know that Ron had watched it three times. However, as Harry replied "me neither", Harry could not have watched Titanic two times. Therefore Ron knows that Harry watched Titanic four times. Next, assume that Ron watched Titanic four times. Initially Ron knows that Harry watched it either three times or five times. At this point Ron does not know if he watched Titanic more than Harry did. Now, let's say that Harry watched Titanic three times. Then Harry initially knows that Ron watched Titanic either two times or four times. In both cases, Ron would not know if he had watched it more times than Harry; thus Ron's reply "I have no idea" does not yet give additional information to Harry. Thus Harry replies "me neither". Ron also knows that Harry would not know the answer yet, whether Harry had watched Titanic three times or five times. Hence Ron also does not know the answer at this point, and therefore Ron wouldn't have replied "yes, indeed!". Therefore Ron did not watch Titanic four times. In a similar manner, if Ron had watched Titanic more than four times, then it would require a longer conversation for Ron and Harry to figure out the answer. In conclusion, Ron could have watched Titanic either 2 or 3 times.

Another riddle I can't solve.!

I can do it in 6 visits. Imagine starting at the center. If that's where they were, you're done. If not, hop to one of the outermost planets. If you happen to hop to the outermost planet on the *correct* arm, you've either just caught them or forced them to hop to the center planet, and you'll catch them on your return. But if you jumped to the outermost planet on one of the two *incorrect* arms, they'll either hop to the center (you'll catch them on your return), or to an outer planet. They cannot at any point leave that arm, so you'll catch them when you reach that arm (or on the hop back to the center afterward). You'll notice that this method requires 7 moves. To get it down to 6, just skip the first visit to the center, it's superfluous. All it would accomplish would be to keep them from switching from one arm you haven't even checked yet to the other arm you haven't checked yet.

The space bandit riddle could be solved way easier if you start at planet 3 and go to planet 2 after that. After that you complete the first sequence because the bandits have to be at an even after the first turn. So it will only take you 6 warps in stead of 10.

Planet 2 looks tasty 😋

0:17 very long pause -- 1:07 barely any time to read -- 1:23 loud volume change -- 4:29 very loud volume change

video: this is planet 4 me: are you sure thats not a marshmallow?

This galaxy sounds very familiar. In my galaxy we have 1-Endor 2-Yavin IV 3-Bespin 4-Tatooine 5-Dagobah 6-well... we used to have Alderaan 7 and Kashyyyk

Ted-d spends more time on the scenario then the riddle itself Change my mind

I love that almost every bridge, or raft, get to the other side riddle, they all wave on the other side.

This video was a lot smarter then I thought it would be, It was quite more challenging then I thought too, maybe I’ll show it to my math teacher.

If you failed this riddle... *”You have failed me for the last time, Officer!”*

STAR WARS REFERENCE!!!!!! :D :D :D 0:19 this makes me very happy because I love Star Wars. Thank you Ted-Ed for making me very happy

Whoa this is insanely time consuming, the amount of paths is just gaaaaaahhhhhhhh

Just get 3 squads and keep them on planets 2,4,and 6

I love the crazy themes of these riddles, now were a galactic patrol member chasing rebels across a funky planet system

or you can just scan for infrared light from the engines firing

Most of the TED-Ed riddle videos I've watched have some instance of poor wording that confuses the riddle. In this case, saying "every time they can relocate, they will." This implies that there are times they can't relocate, rather than just that it takes them an hour to do so. I figured this meant they couldn't relocate to a planet the cops are on, which completely changes the riddle.

All these riddles are so good

Both Harry and Ron have seen Titanic many more times than me because I did not watch it...

This is the best thing of ted-ed

For everyone who thought staying on planet 3 was fine, they could just keep alternating between 2 planets on the outside, meaning you'll never catch them, etc. 7-6 x5, 5-4 x5, or 1-2 x 5, or vice versa, with starting on even numbers instead of odd

Why is no one talking about the Star Wars references at 0:21?

Bonus riddle: Harry has watched it 4-5 times and Ron 3-4. Both results work. Ron and Harry are learning new information with each text, we just have to summarize it. 1: Harry and Ron know that they have watched the movie at least once, so, since Harry asks Ron if he has seen the movie more times than him, we know that Harry has seen it 2 or more times. 2: Since Ron doesn't know the answer, we now know that he hasn't seen it 2 times, but 3 or more, thanks to the new info adquired. 3: Harry answers that he (still) doesn't know either, so he has watched it 4 or more times. 4: Now Ron says that he knows, so he has watched it 3 or 4 times. Both work since we know that Harry has seen it 4+ times, so if Ron knows the answer now, he must have seen it 3 times (and Harry 4 since it's the minimum) or 4 times (and Harry 5, since it can't be the same number). Ron's number can't be 5, because knowing that Harry has watched it 4+ times, he could have seen it 4 or 6 times, so Ron can't be sure about his number being higher.

"Mom, can we have Star Wars?" "We have Star Wars at home." Star wars at home:

“Hey, glass here, I can’t call in for work” “Why, they’re criminals, we need you!” “No... it’s to complicated, and my brain is fried” That would be my excuse if they asked me to do this...

I like how all seven planets are Star Wars references.

If you look closely at 0:12, you can see the info about the criminals. Here they are: Pete: RePete: Height: Height: 3'-ish 3'4.20 Weight: Weight: 80-something lbs 84.71072 lbs Wanted for: Wanted for: General Apathy Specific Larceny

This is a simple strategy that lets you catch them in under 10 moves. 1: Start at the 3rd planet. 2: If they are not there, move to one of the other planets nearby, 6, 2, and 4. 3: If they are not in those planets, they cannot go anywhere else other than back track to the original planet they were in. If they move to 3, we can catch them. If they dont, they back tracked. (If they back track) 4: Move to one of the middle planets. If they arent in the one you went to, they can now only move to the same outer planet or planet 3. You can repeat as much as you want, as long as you do it in under 10 turns.

Solution linked is *behind registration wall*, so no thanks. I was promised a link "straight to the" answer. "Your answer seems reasonable. Find out if you're right! [email/facebook/google+...]" Again, no thanks.

First Ted-Ed riddle I solved

Did anyone see that the bandits names were Pete and RePete?

4:30 Can't you get out. Really. Can't you

1. Endor 2. Yavin-4 3. Bespin 4.Tattooine 5. Dagobah 6. Alderaan 7. Kashyyyk

The riddle was not explained in sufficient detail, i.e. how the moving works, are we warping while they are there or travelling? Who moves first? Because let's say we started at 1. And they are at 2. Clock starts ticking now? Or when they start travelling? Let's say it starts after they land. First move, they go to number 1. Do we decide to warp while they are there? When does our clock start? Let's say we warped to planet 2 while they are at number 1. When does to time start for the new move? If this is like chess, played in turn, how do we know when the other side's turn ended? Bad riddle.

"They must cross over to the left bank of a crocodile infested water." Solution: Wait until the crocodiles die, because that water looks like slime. Then, jump on the corpses and get to the other side :D

*ah yes, one of the planets looks like a big bush with clouds lol*

4:24 Teded - thanks to your deductive reasoning! Me - mine ? 🤔😏

Ted-Ed: Can you solve the seven planets riddle ? Me: Not really. But I'll watch anyway..

Nice Star wars AND Harry Potter in 1 RIDDLE video? This deserves a like.

What is the answer to the bonus riddle?

Id just chill in a random planet and wait for em to get there🤓

Thank you for the video! All of you friends are super awesome!

Harry: How many times hsve you watched Titanic? Ron: I don't know. Me: You never watched the Titanic!? It already sunk before you.

"Every time they can relocate, they will." Does this mean that if the cops are on the planet they would have to move to (say they are on the outside and the cops are one planet inward), then they *can't* relocate, therefore they won't? If you follow the list instructions when they summarize it, it says that they MUST move every hour. So there is no implication that there is any situation where they can't. See, I have a solution that works if they absolutely must move each hour, guaranteed, and it gets them in 7 moves if that is the case. So... honestly this feels important to know for sure. The use of the word "can" implies there might be a situation where they can't (blocked route), yet the use of the word MUST (in all caps in the video even) tells me that there's no such situation. So what's the deal? Would my solution be valid?

I love the star wars rearranged names!

I feel like I'd just sit at the middle planet cause I'd be too lazy too go around the planets-